Knitted artefact with heat shrinking yarns

ABSTRACT

An assembly is described for chairs, armchairs, sofas and the like, comprising a knitted artefact ( 1 ) and sliders ( 12 ). The artefact ( 1 ) comprises a multilayer and two ends ( 11 ) of tubular shape for fixing the multilayer, wherein the multilayer comprises a knitted fabric front layer ( 2 ) and a knitted fabric rear layer ( 3 ) fixed to sliders ( 12 ) of the artefact ( 1 ) at said two ends ( 11 ). The artefact ( 1 ) further comprises heat-shrinking yarns ( 5 ) associated with the multilayer, wherein the heat-shrinking yarns ( 5 ) are fixed with a series of connection points ( 7 ) spaced apart to the sliders ( 12 ) so as to develop in weft between the two ends ( 11 ) of the artefact ( 1 ).

BACKGROUND OF THE INVENTION

The present invention relates to a knitted artefact with heat-shrinking yarns.

The search for comfort combined with lightness, cost-effectiveness and ease of assembly, has led chair, armchair and sofa manufacturers to look with interest at the knitwear sector.

It is now widespread to make seats and backrests of knitted fabrics, namely with the interlacing of yarns useful to confer given technical characteristics.

The present applicant is the holder of the Italian patent application No. 102019000011508, which describes a modular chair fabric comprising a periodic interlacing with at least one main yarn, in which a secondary yarn is arranged in a weft along a predetermined trajectory.

The main fabric may include cushioning elements trapped between two layers of knitted fabric, namely a front layer and a back layer.

The secondary yarn may be woven into the knitted fabric or simply inserted between said knitted fabric layers.

The main yarn interlocking may define a plurality of tubular portions within which one or more secondary yarns are inserted.

The secondary yarn defines different characteristics with respect to the main yarn, e.g. thermal properties, namely it can undergo elongation or shrinkage proportional to the application or subtraction of heat, namely the secondary yarn can be of the heat-shrinking type.

The main yarn and the secondary yarn are mutually bonded at two perimetric areas of the fabric. Said bonding takes place by means of a slider inserted in said tubular perimeter areas. The secondary yarn is bound to the slider with an “English” type hook in the tubular area, as usually occurs between the yarn and the knitting needle.

The “English” type hook, also known as English knitting or right-hand knitting or throwing, is a known style of western knitting where the yarn to be knit into the fabric is carried in the right hand. This style is prevalent throughout the English-speaking world, though it is by no means universal. Other Western knitting styles include continental knitting (also known as “left-hand knitting”) and combined knitting.

Relating to the English knitting technique, assuming that there are already stitches on the needles, having been cast on previously, the yarn is wrapped around the right hand for tension (in one method, the tail of the yarn is wrapped around the little finger of the right hand for tension, and over the index finger for control). The right hand will hold the needle with the most recently knit stitches. If at the beginning of a row, the right hand will hold the empty needle. The left hand holds the other needle.

Known knitting machines are able to apply the English knitting technique.

In the applicant's previous patent application, if the secondary yarn has thermal properties, namely it is a heat-shrinking yarn, the fabric shrinks as a result of the application of heat. Said shrinkage raises the fabric creating a padding effect even in the absence of padding between the front layer and the back layer. In the presence of padding, said shrinkage causes the raising of padded sections processed in alternation to the heat-shrinking type yarn.

Disadvantageously, the user feels the heat-shrinking yarns, which are inherently much stiffer than the yarns of the knitted fabric of the front layer on which the user rests directly.

The raising effect that the heat-shrinking yarns generate on the fabric amplifies the discomfort of the support, especially if it is a seat.

Furthermore, with the use, strips are created also visually at the heat-shrinking yarns which alter the original appearance of the fabric.

WO-2018/134743 describes a multilayer knitted artefact comprising a heat-shrinking yarn inserted and connected by stitching to a layer of knitted fabric or made from conventional fabrics or leather. Said artefact is suitable for use in accessories such as bags, sofas, jackets and shoes.

Disadvantageously, a very rigid artefact is produced, which is the object of WO-2018/134743.

DE-102014003099, JP-2015221112 and US-2015/173514 disclose knitted fabrics for chairs comprising heat shrinkable material.

SUMMARY OF THE INVENTION

It is the object of the present invention is to make an assembly comprising a knitted artefact with heat-shrinking yarns, comfortable for a resting user.

It is a further object of the present invention that said artefact is easily associated with a supporting structure of a chair, a sofa, an armchair and the like.

It is a yet further object of the present invention that said artefact is easy to make, in a short time and that it resists to the passing of time maintaining a pleasant comfort of the product in which it is integrated.

According to the invention, said and further objects are achieved by an assembly for chairs, armchairs, sofas and the like, as disclosed in the claims.

Advantageously, the artefact only shrinks underneath, namely only the knitted fabric rear layer shrinks.

As a result, a distancing movement of the knitted fabric front layer away from the knitted fabric rear layer is achieved, namely a three-dimensional effect considering the bonding of the knitted fabric front layer with the slider at the ends.

The independence of the heat-shrinking yarns from the knitted fabric front layer allows the latter to remain flexible and deformable.

Advantageously the knitted fabric front layer undergoes a completely different technical effect with respect to the knitted fabric rear layer.

The artefact according to the present invention meets the user's comfort needs with simple, automated and cost-effective technical means.

DESCRIPTION OF THE DRAWINGS

These and other features of the present invention will become further apparent from the following detailed description of practical embodiments thereof illustrated by way of non-limiting example in the accompanying drawings, in which:

FIG. 1 shows a front perspective view of a portion of an artefact according to the present invention;

FIG. 2 shows a rear perspective view of a portion of the artefact;

FIG. 3 shows a perspective bottom view of an end portion of the artefact;

FIG. 4 shows the enlarged content of circle B of FIG. 1;

FIG. 5 shows a side view of a portion of the artefact.

DETAILED DESCRIPTION OF THE INVENTION

A knitted artefact 1 for chairs, armchairs, sofas and the like, comprises a knitted fabric front layer 2, a knitted fabric rear layer 3 and, where appropriate, a padding between said layers 2, 3. Knitted fabric front layer 2 means the layer with which a user comes into contact. Chairs and armchairs are generally understood to be products for the seating of users, e.g. car seats, aircraft seats, wheelchairs and more.

The padding consists of a filament weave which can be connected to the layers 2, 3 by machine or inserted in the gap between layers 2, 3 without any particular bonding.

The artefact 1 further comprises a plurality of heat-shrinking yarns 5.

The layers 2, 3 form a tubular knitted multilayer.

The artefact 1 comprises two tubular ends 11.

The heat-shrinking yarns 5 are connected to the ends 11 of the artefact 1 at sliders 12 inserted in said ends 11 which develop in an orthogonal direction with respect to the heat-shrinking yarns 5.

As apparent in FIG. 3, the layers 2, 3 are connected at these ends 11.

The heat-shrinking yarns 5 develop in weft between the two ends 11 at which they wind to have a solid bond.

Said ends 11 of the artefact 1 allow the attachment to rigid supporting structures of the chair, sofa or armchair, thus forming seat assemblies that therefore comprise a supporting structure and a supporting knitted fabric comprising said artefact 1.

The layers 2, 3 create a tubular structure which can enclose a padding, while the heat-shrinking yarns 5 are positioned outside the knitted fabric rear layer 3 (FIGS. 2 and 3), namely the layer which is not visible in a seat or not in contact with the user, for example a rear portion of a chair backrest.

A discrete set of appropriately spaced connection points 7 binds the heat-shrinking yarns 5 on the outside of the knitted fabric rear layer 3 with a type of hook known as “English”.

The heat-shrinking yarns 5 are free on the knitted fabric rear layer 3, between the two ends 11, within said connection points 7.

Preferably a connection point 7 is provided at least every five beatings of the knitted fabric rear layer 3, wherein beating means a direction of adjacent rows of warp yarns of the knitted fabric rear layer 3. At least every five beatings means that it can be every five or more beatings.

Preferably, the number of heat-shrinking yarns 5 is less than 20% of the total yarns of the artefact 1, even more preferably between 3% and 8%.

Advantageously the technical effect described below is optimized by increasing the cost-effectiveness of the final product.

Even at the ends 11, the heat-shrinking yarns 5 are hooked “in English” with connection points 7. The heat-shrink yarns 5 are wound to the sliders 12 thus creating a solid connection.

Once the artefact 1 has been made with the heat-shrinking yarns 5 configured in a straight line between the ends 11, as shown in FIGS. 2 and 3, heat is applied to the knitted fabric rear layer 3, e.g. steam, and said heat-shrinking yarns 5 shrink permanently and irreversibly due to their intrinsic properties.

Advantageously the artefact 1 shrinks only underneath, namely only the knitted fabric rear layer 3 shrinks.

The knitted fabric front layer 2 does not shrink because the heat-shrinking yarns 5 are not bound to the knitted fabric front layer 2.

As a result, a distancing movement of the knitted fabric front layer 2 away from the knitted fabric rear layer 3 is achieved, namely a three-dimensional effect considering the bonding of the knitted fabric front layer 2 with the slider 12 at the ends 11. In the case of a seat, said movement consists of a raising of the knitted fabric front layer 2, namely a padding effect is achieved. In the absence of padding between the two layers, a real pocket is created.

In case of processing a padding in parallel between the layers 2, 3, the permanent shrinkage of the heat-shrinking yarn 5 prevents the extension and flattening of the simultaneously processed padding in the gap between the two layers 2, 3. The padding tends to flatten when extended and remains raised. Therefore, once the artefact 1 is tensioned in the chair assembly, the padding remains hanging on the knitted fabric rear layer 3 to which the heat-shrinking yarns 5 are hooked “in English” under tension.

Said technical effect also varies according to the number of heat-shrinking yarns 5.

The presence of padding also varies said technical effect; if the padding is processed simultaneously with layers 2, 3, the machine programming can define padding of variable density and height.

The independence of the heat-shrinking yarns 5 with respect to the knitted fabric front layer 2 allows the latter to remain flexible and deformable.

The function of the sliders 12 at ends 11 is very important because they define a stable bond for both the layers 2, 3 and the heat-shrinking yarns 5, without the shrinkage effect of the heat-shrinking yarns 5 being applied to the knitted fabric front layer 2.

Advantageously the knitted fabric front layer 2 undergoes a completely different technical effect with respect to the knitted fabric rear layer 3.

The artefact 1 according to the present invention meets the user's comfort needs with simple and cost-effective technical means.

Said technical effect is even more pronounced when the knitted fabric front layer 2 is of the “origami” type, namely it has an intrinsic three-dimensional deformability. It is worth noting that in FIGS. 1, 4 and 5, the knitted fabric front layer 2 is of the “origami” type, but this technical distancing effect is present even if the knitted fabric front layer 2 is of the standard type, namely not of the “origami” type.

In more detail, in the artefact 1, the knitted fabric front layer 2 of the “origami” type comprises a plurality of plastic elements 21 spaced apart to create the “origami” effect, namely a three-dimensional deformability, in particular in a direction orthogonal to the surface of the fabric.

The knitted fabric front layer 2 of the “origami” type is made using a 3D printing process (3D printer), or preferably a plastic injection moulding process.

It is generally a plastic moulding process which takes place starting from an artefact 1 already comprising said knitted fabric layers 2, 3 fixed to the sliders 12 at the ends 11, and the heat-shrinking yarns 5 hooked “in English” under the knitted fabric rear layer 3 and at the ends 11.

In more detail, the knitted fabric front layer 2 is placed on a support, preferably metallic, e.g. aluminium, to isolate the knitted fabric rear layer 3 during the process of adding plastic material. Basically, the support is interposed between the layers 2, 3.

The plastic material printed on top of the knitted fabric front layer 2 creates a plurality of plastic elements 21 which integrate with the knitted fabric front layer 2 conferring localized rigidity to the knitted fabric front layer 2. FIG. 5 shows how the plastic elements 21 penetrate the knitted fabric front layer 2.

Advantageously, the knitted fabric rear layer 3 is not affected by the process of adding plastic material.

Said plastic elements 21 have a variable design according to the printing control or the shape of the mould and are spaced to leave areas in the knitted fabric front layer 2 free from plastic elements 21.

Advantageously, said free areas of fabric are deformable, thus allowing three-dimensional deformability of the knitted fabric front layer 2 of the “origami” type.

At the end of the printing process, the knitted fabric front layer 2 of the “origami” type is easily separated from the support because said free areas of fabric create contact discontinuities following the creation of the plastic elements 21.

Once the plastic elements 21 have been made, heat is applied to the knitted fabric rear layer 3 which contains the heat-shrinking yarn 5: advantageously, the knitted fabric rear layer 3 shrinks.

Since the two layers 2, 3 are bound at the ends 11, this shrinkage causes a shortening of the distance between the two sliders, thus raising/activating the origami-shaped plastic elements 21.

If the knitted fabric front layer 2 is of the “origami” type, no padding is required between the layers 2, 3 because the three-dimensional effect is given by the origami. 

1. Assembly for chairs, armchairs, sofas and the like, comprising a knitted artefact and sliders, wherein the artefact comprises a multilayer and two ends of tubular shape for fixing the multilayer, wherein the multilayer comprises a knitted fabric front layer and a knitted fabric rear layer fixed to the sliders at the two ends, wherein the artefact also comprises heat-shrinking yarns fixed to the multilayer, wherein the heat-shrinking yarns are fixed with a series of connection points spaced apart to the sliders so as to develop in weft between the two ends of the artefact, wherein the heat-shrinking yarns are fixed to the knitted fabric rear layer at an external part of the knitted fabric rear layer, with a further series of the connection points spaced apart, the knitted fabric front layer comprises a plurality of plastic elements spaced apart, the plastic elements penetrate the knitted fabric.
 2. The assembly according to claim 1, wherein a connection point is provided for every five or more beatings up of the knitted fabric rear layer.
 3. The assembly according to claim 1, wherein the number of the heat-shrinking yarns is less than 20% of total yarns of the artifact.
 4. The assembly according to claim 2, wherein the number of the heat-shrinking yarns is between 3% and 8% of total yarns of the artefact.
 5. The assembly according to claim 1, wherein the multilayer comprises a padding between the knitted fabric front layer and the knitted fabric rear layer.
 6. The assembly according to claim 1, wherein the artefact has a tubular shape between the two ends. 